Immunochemical and biochemical aspects of the plasma-kinin system and alpha l-antitrypsin in man and animals will be studied in general and as they relate to the normal and diseased lung. The study of the activation of the kinin system and the inactivation of formed bradykinin will be continued in in vitro systems, and clinical studies will be performed on the status of the kinin system in the respiratory distress syndrome of the newborn, patients with carcinoid tumors and other clinical disease states. Further studies on the molecular basis for the polymorphism of the alpha1-antitrypsin in man will be performed. The significance of this protein in the normal lung, as well as in a variety of pulmonary diseases will be studied. There will be an emphasis on the various clinical reasons for lowering of normal alpha1-antitrypsin levels.